The present invention relates to a composite coating device for forming a composite coating on a magnetic head and a method of forming a composite coating on a magnetic head.
In a magnetic storage device, a magnetic head is used to record and retrieve data stored in a magnetic storage media. For example, in a hard drive (HD) magnetic storage device in which data is recorded on a magnetic disk, when a magnetic head records and retrieves (access) data, the magnetic head rises from a disk surface only for a predetermined distance. When the magnetic head does not access data, the magnetic head lands on the disk surface in a so-called CSS (contact start and stop) mechanism.
As described above, when the magnetic head does not access data, the magnetic head receives a shock from the disk. The magnetic head also receives a corrosive action through atmospheric moisture and the like, so that wear resistance and corrosion resistance are required for an overcoat of the magnetic head. In addition, as the recording density has been increasing, it is required to reduce a thickness of the overcoat to reduce a distance between an electrode of the magnetic head and a recording layer on the magnetic disk (flight height).
In general, an overcoat of the magnetic head is formed through a manufacturing process comprising (1) a pretreatment process in which a coating surface of a head body is cleaned; (2) a shock absorbing coating formation process in which an amorphous silicon coating is formed; and (3) an overcoat formation process in which a DLC coating is formed. A composite coating device is used to carry out the processes in three independent processing chambers, respectively. The composite coating device performs a sputter etching for the pretreatment process, sputter deposition for the shock absorbing coating formation process, and electron cyclotron resonance plasma chemical vapor epitaxy or cathode arc discharge deposition for the overcoat formation process (refer to Japanese Patent Publication (Kokai) No. 2001-195717).
When the sputter etching is used for the pretreatment process, there is the following problem. An overcoat is formed on a surface of a magnetic head. The surface includes a portion formed of a soft electrode metal, for example, Permalloy, and a portion formed of a hard base metal, for example, AlTic (Al2O3TiC). Accordingly, the portions of the surface are etched at different etch rates, i.e. the portion formed of Permalloy is etched at a higher speed, thereby forming a recessed portion on the surface. As a result, the flight height increases, thereby making it difficult to obtain high recording density.
In view of the problem described above, an object of the present invention is to provide a composite coating device and an overcoat formation method, in which an overcoat is formed on a magnetic head while a flight height in the magnetic recording is reduced.
Further objects and advantages of the invention will be apparent from the following description of the invention.